unix2dos

=============================== unix2dos.cpp ===============================

// converts Unix text files to DOS format by replacing \n with \r\n

#include <stdio.h>
#include <dir.h>
#include "readahead.h"

void main(int argc, char **argv)
{
  for (int i = 1; i < argc; i++)
  {
    readahead *f = new readahead(argv[i], 3);
    printf("%s:\n", argv[i]);
    if (!f->open())
    {
      fputs("Can't open file\n", stderr);
      continue;
    }
    FILE *t = tmpfile();
    while ((*f)[0] != EOF)
    {
      if ((*f)[0] == '\r' && (*f)[1] == '\n')
      {
        fputc('\n', t);
        f->advance(2);
      }
      else if ((*f)[0] == '\n')
      {
        fputc('\n', t);
        f->advance(1);
      }
      else
      {
        fputc((*f)[0], t);
        f->advance(1);
      }
    }
    delete f;
    rewind(t);
    FILE *ff = fopen(argv[i], "w");
    if (ff == NULL)
    {
      fputs("Can't modify file\n", stderr);
      continue;
    }
    int c;
    while ((c = fgetc(t)) != EOF)
      fputc(c, ff);
    fclose(t);
    fclose(ff);
  }
}

=============================== readahead.cpp ===============================

// File reading package with read-ahead

#include "readahead.h"

readahead::readahead(const char *filespecs, unsigned size, bool binary)
{
  psize = size;
  buffer = new int[psize];
  fp = fopen(filespecs, binary ? "rb" : "r");
  eof = fp == NULL;
  unsigned i;
  for (i = 0; i < psize; i++)
    buffer[i] = get();
}

readahead::~readahead()
{
  if (open())
  {
    delete [] buffer;
    fclose(fp);
    fp = NULL;
  }
}

void readahead::advance(unsigned count)
{
  while (count > 0)
  {
    unsigned i;
    for (i = 0; i < psize-1; i++)
      buffer[i] = buffer[i+1];
    buffer[i] = get();
    count--;
  }
}

int readahead::get(void)
{
  int c;
  if (eof)
    c = EOF;
  else
  {
    c = fgetc(fp);
    if (c == EOF)
      eof = true;
  }
  return c;
}

bool readahead::match(const char *s) const
{
  int i;
  for (i = 0; s[i] != 0; i++)
  {
    if (s[i] != (char) buffer[i])
      return false;
  }
  return true;
}

=============================== readahead.h   ===============================

#ifndef H__READAHEAD
#define H__READAHEAD

#include <stdio.h>

class readahead
{
  public:
    readahead(const char *filespecs, unsigned size, bool binary = false);
    ~readahead();
    bool open() const {return fp != NULL;}
    int operator [](int i) const {return buffer[i];}
    void advance(unsigned count = 1);
    bool match(const char *s) const;
  private:
    int *buffer;
    unsigned psize;
    FILE *fp;
    bool eof;
    int get(void);
};



#endif